Why are there roses planted at the end of each row of vines?
Both roses and grape vines are susceptible to some of the same diseases. Indeed, roses act as early warning of mildew which is a fungal disease. There are two main kinds of mildews: Powdery mildew (Oidium) that develops on all green parts of the vine. We can see white powdery growth of spores on the surfaces. If this mildew sets on the grapes, the fruit will not grow properly and will eventually split and rot. This fungus likes a warm and shady environment and does not need a damp condition to survive.
The second deadly mildew is called Downy mildew. It attacks all the green parts of the vine and leaves behind patches of oily stains on the surface. Once attacked, the leaves will drop and photosynthesis is inhibited. This fungus likes damp conditions unlike that of Oidium.
Both fungus diseases can be treated by sprays of sulphur (for powdery mildew) and copper sulphate + lime solution (for downy mildew) once detected. Rose bushes help the vineyard team to catch sights of the fungus disease in its early stage to apply the proper treatment.
That being said, many a vineyard manager would smile at this quaint romantic notion. Their job is more sophisticated than watching the roses bloom. In these days of modern technology roses are planted at the rows end for purely cosmetic reasons, but don't let that spoil another great story...
Some time ago in the Hunter Valley in New South Wales I quizzed one of the “old timers” in the area about the same issue. His response left me wondering whether or not he was “having a lend of me”.
In the early days of grape growing, before any mechanisation, the vineyard work was completed using horses and horse pulled equipment. The best source of strong “draught horses” were the local coalmines where any pulling work involved horses.
Sadly the distance underground was so far that the horses used were stabled in areas deep underground and, while they were very well cared for, their eyesight eventually became a casualty of the environment. The period horses were kept underground was mercifully short but permanent damage to their vision occurred. As the horses were “traded out” the local farmers and grape growers sought to utilise their great strength and stamina, particularly working with ploughs in vineyards where the rows were quite narrow.
Now the reason for the roses at the ends of the rows, as explained by this particular veteran, was to let the ‘blind’ horses know when they reached the end and it was time to turn. Roses in the Hunter Valley constantly bloom almost all year. I was never able to convince myself either way with his story; Australians can be very straight-faced when “spinning a yarn”. I will leave it up to you to decide.